Troubleshooting the Power Subsystem
—If the answer is no, but the fan trays are operating and the alphanumeric displays on the RP and line cards are functional, the likely suspect is a faulty power supply LED.
The MBus modules driving the alphanumeric displays are powered by +5.2 VDC from the power supply.
The fan trays are powered by +24 VDC from the
You can issue the show environment command at the user EXEC mode prompt to display temperature and voltage information for each installed card in the system.
—If the answer is no and there is no other obvious system activity, verify that the rotary power switch on the power supply is in the fully clockwise ON () position. If it is not, turn the power switch clockwise until you hear an audible click, ensuring that the switch is in the full ON position and that the latching mechanism has been engaged.
•If the rotary power switch is set correctly and the AC INPUT OK LED (on the
If the internal circuit breaker of the power supply has been tripped, you can reset it by turning the rotary power supply switch OFF then ON again. However, note that the tripping of the internal circuit breaker is a likely indication of an electrical problem in the chassis.
•Turn the rotary power switch OFF (O); check the state of the source AC or DC circuit breaker, as appropriate. Verify that the breaker is ON and that it has not been tripped. Verify that the source circuit breaker has the proper current rating.
Note Each power supply in the Cisco 12008 should be attached to a separate power source.
•In systems powered by source AC, there might be an uninterruptable power supply (UPS) for each installed
Troubleshooting the Installation
